You can (will) call it insults whatever I say, eloethan, so I'll agree with you. It's an insult, several insults even, directed at some prevalent attitudes on some GN threads. If attitudes are people then the quote is insulting to people who hold and display those attitudes.
I make no apology for being insulting about attitudes that I find reprehensible. I make no apology for repeating insulting phrases about attitudes and, if you like, the people who show such attitudes anywhere, not just on GN. If someone can tell me a better way to get across my disgust at such attitudes, a non-insulting way, then I'm all ears to learn. Fire away.
But I still think such crap attitudes need to be insulted. This is the right use of what some people choose to call insulting language as far as I'm concerned.
Just for info, it was a lifelong Labour voter (but not someone I know personally) who wrote it.